Copper (II) sulfate, also known as cupric sulfate or copper sulphate, is the chemical compound with the chemical formula CuSO4. This salt exists as a series of compounds that differ in their degree of hydration. The anhydrous form is a pale green or gray-white powder, whereas the pentahydrate (CuSO4·5H2O), the most commonly encountered salt, is bright blue. Copper sulfate exothermically dissolves in water to give the aquo complex [Cu(H2O)6]2+, which has octahedral molecular geometry and is paramagnetic. Other names for copper (II) sulfate are "blue vitriol" and "bluestone".
Copper (II) sulfate pentahydrate decomposes before melting at 150°C, losing two water molecules at 63°C, followed by two more at 109 °C and the final water molecule at 200°C.
Agricultural chemicals
Feeds
Germicides - in the textile and leather industries
Pigments
Electric batteries
Reagent in analytical chemistry
Medicine
Wood preservative
For engraving and lithography
Mining and petroleum industries
Synthetic rubber
Steel manufacture
Asphalts manufacture
The anhydrous salt is used as a dehydrating agent
Copper sulfate is employed in ceramics for metallic coloration
and so on.
Specifications of Cupric sulfate or Copper Sulphate Pentahydrate Commercial Pure
Parameters -------- Specification
Appearance --------- Blue Colored Powder & Crystals
Copper as Cu % ----- 24.50 Min
Nickel as Ni % ----- 0.03 Max
Iron as Fe % ------- 0.20 Max
Lead as Pb % ------- 0.002 Max
Cadmium as Cd % ---- 0.001 Max
Arsenic as As % ---- 0.0005 Max
Mercury as Hg % ---- 0.0005 Max
Insoluble matter % - 0.02 Max in water
pH in 5% Solution -- 3.50 Min
Cupric Sulfate CuSO4-5H2O --- 249.7 --- 7758-99-8
DEFINITION
Content: 99.0 per cent to 101.0 per cent.
CHARACTERS
Appearance: Blue, crystalline powder or transparent, blue crystals.
Solubility: Freely soluble in water, soluble in methanol, practically insoluble in ethanol (96 per cent).
IDENTIFICATION
A. Add several drops of dilute ammonia to 1 ml of solution S (see Tests). A blue precipitate is formed. On further addition of dilute ammonia the precipitate dissolves and a dark blue colour is produced.
B. Loss on drying (see Tests).
C. Dilute 1 ml of solution S to 5 ml with water. The solution gives reaction of sulphates.
TESTS
Solution S: Dissolve 5 g in water and dilute to 100 ml with the same solvent.
Appearance of solution: Solution S is clear.
Chlorides: Maximum 100 ppm.
Iron: Maximum 1.00 × 102 ppm.
Atomic absorption spectrometry: To meet the requirement.
Lead: Maximum 50.0 ppm.
Loss on drying: 35.0 per cent to 36.5 per cent, determined on 0.500 g by drying in an oven at 250 ± 10 °C.
Identification: A solution (1 in 10) responds to the tests for Copper and for Sulfate.
Loss on drying: Dry it at 250 to constant weight: it loses between 33.0% and 36.5% of its weight.
Limit of sodium: The limit is 0.02%.
Limit of potassium: The limit is 0.01%.
Limit of calcium: The limit is 0.005%.
Limit of iron: The limit is 0.003%.
Limit of nickel: The limit is 0.005%.
CuSO4 Formula wt, anhydrous 159.6
CuSO4·5H2O Formula wt, pentahydrate 249.68
INS: 519 CAS: anydrous [7758-98-7]
CAS: pentahydrate [7758-99-8]
DESCRIPTION
Copper Sulfate occurs as blue crystals, crystalline granules, or powder. It effloresces slowly in dry air and is freely soluble in water, soluble in glycerin, and slightly soluble in alcohol.
Function: Nutrient.
REQUIREMENTS
Identification: A 1:20 solution gives positive tests for Copper and for Sulfate.
Assay: Not less than 98.0% and not more than 102.0% of CuSO4·5H2O.
Iron: Not more than 0.01%.
Lead: Not more than 4 mg/kg.
Substances Not Precipitated by Hydrogen Sulfide: Not more than 0.3%.
Copper(II) Sulfate Pentahydrate
CuSO4 · 5H2O Formula Wt 249.68
CAS Number 7758–99–8
REQUIREMENTS
Assay: 98.0–102.0% as CuSO4 · 5H2O
MAXIMUM ALLOWABLE
Insoluble matter: 0.005%
Chloride (Cl): 0.001%
Nitrogen compounds (as N): 0.002%
Calcium (Ca): 0.005%
Iron (Fe): 0.003%
Nickel (Ni): 0.005%
Potassium (K): 0.01%
Sodium (Na): 0.02%
Parameters -------- Specification
Appearance --------- Blue Colored Powder & Crystals
Copper as Cu % ----- 38.2 Min
Nickel as Ni % ----- 0.05 Max
Iron as Fe % ------- 0.30 Max
Lead as Pb % ------- 0.003 Max
Cadmium as Cd % ---- 0.001 Max
Arsenic as As % ---- 0.0007 Max
Mercury as Hg % ---- 0.0007 Max
Insoluble matter % - 0.03 Max in water
All other parameters as above depending on degree of drying as monohydrate or anhydrous.
